According to files from the British agency from between 2008 and 2010, a surveillance program code-named Optic Nerve collected still images from private webcam chats from Yahoo users around the world, regardless of whether they were being targeted for surveillance.
The classified documents, which are part of a trove of information leaked by former NSA analyst Edward Snowden, also reveal that a substantial quantity of the webcam images collected by the Government Communications Headquarters (GCHQ) was sexually explicit in nature, and that the agency struggled to figure out how to handle the stores of sensitive material.
During a six-month period in 2008, the Optic Nerve program accessed images from 1.8 million Yahoo accounts around the world, although it's not clear how many accounts in total were affected. The users were "unselected," meaning they weren't necessarily targeted for surveillance, The Guardian says.
Yahoo responded to the report, calling the surveillance program "a whole new level of violation of our users' privacy."